This is a helpful list from Good Housekeeping Magazine, 1958. What is interesting is how many of these warning still apply...Buyer Beware!

There are many good sewing machines on the market today, in a wide range of prices, Unfortunately, some dealers use questionable selling practices to push a particular machine or to obtain a higher price for it than it sells for elsewhere. This situation exists predominantly in the field of sewing machines, although to some extent it also involves vacuum cleaners and other appliances. Here are some practices that may be outright trickery.

Fake "contests," in which the solution is obvious ("Count the number of Santa Clauses in this ad") and the prize is a "substantial reduction from the regular price of the machine. The catch? The "reduced price" is the price the same or comparable machines customarily sell for elsewhere.

Bait advertising, in which a machine is advertised at a very low price. When you go to buy it, however, you find that it is "nailed to the floor"-i.e., the dealer belittles it, tries to pressure you into buying a higher price model.

Phony offers, such as "free trial' or "refund if you're not completely happy with our machine." Once you've had a machine delivered to your home, you may find you're obligated to pay for it, satisfied or not.

Worthless guarantees. Blank guarantees or those signed by a dealer alone are no real protection unless the dealer is long-established and reputable. A guarantee is only as good as the party offering it.

"Flying squad" salesman. Representing a "dealer" you've never heard of, they canvass a town from door to door, offer "bargain" prices, then move on. If a machine bought this way turns out to be faulty, there is no one to complain to or obtain service from.

Inflated list prices. These are sometimes quoted to make an advertised "sale" price look good. Often, however, the true list price and the so-called sale price are about the same.

Other lures. "Earn a sewing machine by making garments in your spare time." (Selling the garments is left up to you; the dealer will not accept them in part payment ior the machine.) "A huge trade-in for your old machine." (This can mean that the price of the new machine will be inflated as well.)

"We give an advertising allowance." (This "allowance," if any, is often made only if sales are made to friends and acquaintances, whose names you supply.)

Sometimes dissatisfaction with a machine is the customer's own fault. To avoid disappointment, follow these rules when you buy.

Make sure you read and understand the terms of any contracts, agreements, receipts, etc., you sign.

If you decide on a low-price machine, don't expect it necessarily to give you the added features and performance of a more expensive model. And be sure that you sit down and try the machine.

If you buy an automatic zigzag machine, expect to study its operation to gain skill, no matter how experienced you are on a straight-stitch machine.

Don't buy a machine on the installment plan if the terms are likely to be a hardship. In these circumstances, a slight defect may become magnified in your eyes, make you unreasonably dissatisfied with your purchase.

Don't think that you're driving a shrewd bargain if you seem to be talking a dealer out of every cent of profit on a transaction. He is not in business for his health, and if you force the basic price of the machine down too far, he may more than make it up in hidden extras, such as charges for delivery, service, or lessons ordinarily provided free.